<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<style>

.content {
    width: 200px;
    height: 2rem;
    line-height: 2rem;
    background: lightskyblue;
    clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 100%, 0 100%);
}

</style>

<body>
    
    <div class="content">
        这是标题
    </div>

</body>
</html>